IDC Port max current

I'm willing to connect a 7" Nextion display to the industruino. Since I won't be using any expansion modules, the 14-pin IDC port will be free.

I want to connect the RX/TX from the display to the same connections on the 14-pin IDC port, but I'm wary of connecting the 5V and GND as well. Should I use an external power supply for the display?

The nextion display has a typical max current of 510mA.
Thanks in advance!

Jarne
Jarne
19
| 1 1 1
Asked on 2/19/20, 8:53 AM
1
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1418 Views

hi, it looks like you will need an extra power supply, because the 5V on the IDC can only deliver around 350mA. the Industruino's DC/DC converter (V+/V- to 5V) is 2W, so can supply 400mA max: the topboard needs around 50mA, depending on the LCD backlight, so 350mA is available on the IDC 5V.

Just for reference, a Nextion setup via RS485 https://industruino.com/blog/our-news-1/post/nextion-hmi-with-industruino-42

Tom
Tom
5675
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Answered on 2/20/20, 12:18 AM
3
vote

Hi.... the allowable LED current is pretty much dictated by allowable junction temperature.  However, the allowable PIC pin current is limited by other factors too, and it has quite different electrical characteristics.  High PIC pin current can cause voltage drops in other parts of the chip.  Also a PIC output pin looks mostly like a resistor to Vdd or Vss since it's implemented by a turned on MOSFET. 

GustaBertie
GustaBertie
14
| 0 0 0
Answered on 3/2/20, 5:43 PM
1
vote

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Asked: 2/19/20, 8:53 AM
Seen: 1418 times
Last updated: 3/2/20, 5:43 PM